VServer 1.9.2 (patch-2.6.8.1-vs1.9.2.diff)

[linux-2.6.git] / drivers / i2c / chips / lm75.c

diff --git a/drivers/i2c/chips/lm75.c b/drivers/i2c/chips/lm75.c
index e431db9..3752a27 100644 (file)
--- a/drivers/i2c/chips/lm75.c
+++ b/drivers/i2c/chips/lm75.c
@@ -113,7 +113,7 @@ static int lm75_attach_adapter(struct i2c_adapter *adapter)
 /* This function is called by i2c_detect */
 static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
 {
-       int i, cur, conf, hyst, os;
+       int i;
        struct i2c_client *new_client;
        struct lm75_data *data;
        int err = 0;
@@ -149,16 +149,41 @@ static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
        new_client->driver = &lm75_driver;
        new_client->flags = 0;
 
-       /* Now, we do the remaining detection. It is lousy. */
+       /* Now, we do the remaining detection. There is no identification-
+          dedicated register so we have to rely on several tricks:
+          unused bits, registers cycling over 8-address boundaries,
+          addresses 0x04-0x07 returning the last read value.
+          The cycling+unused addresses combination is not tested,
+          since it would significantly slow the detection down and would
+          hardly add any value. */
        if (kind < 0) {
+               int cur, conf, hyst, os;
+
+               /* Unused addresses */
                cur = i2c_smbus_read_word_data(new_client, 0);
                conf = i2c_smbus_read_byte_data(new_client, 1);
                hyst = i2c_smbus_read_word_data(new_client, 2);
+               if (i2c_smbus_read_word_data(new_client, 4) != hyst
+                || i2c_smbus_read_word_data(new_client, 5) != hyst
+                || i2c_smbus_read_word_data(new_client, 6) != hyst
+                || i2c_smbus_read_word_data(new_client, 7) != hyst)
+                       goto exit_free;
                os = i2c_smbus_read_word_data(new_client, 3);
-               for (i = 0; i <= 0x1f; i++)
-                       if ((i2c_smbus_read_byte_data(new_client, i * 8 + 1) != conf) ||
-                           (i2c_smbus_read_word_data(new_client, i * 8 + 2) != hyst) ||
-                           (i2c_smbus_read_word_data(new_client, i * 8 + 3) != os))
+               if (i2c_smbus_read_word_data(new_client, 4) != os
+                || i2c_smbus_read_word_data(new_client, 5) != os
+                || i2c_smbus_read_word_data(new_client, 6) != os
+                || i2c_smbus_read_word_data(new_client, 7) != os)
+                       goto exit_free;
+
+               /* Unused bits */
+               if (conf & 0xe0)
+                       goto exit_free;
+
+               /* Addresses cycling */
+               for (i = 8; i < 0xff; i += 8)
+                       if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
+                        || i2c_smbus_read_word_data(new_client, i + 2) != hyst
+                        || i2c_smbus_read_word_data(new_client, i + 3) != os)
                                goto exit_free;
        }